Statement (1) is insufficient: if x = 1 and y = 6, xy is less than 7; if x = 3 and y = 4, xy is greater than 7.

Statement (2) is also insufficient: if you take the smallest possible numbers, x = 1 and y = 2, xy is less than 7; if you take the largest possible numbers, x = 3 and y = 4, xy is greater than 7.

Taken together, the statements are sufficient. Given the ranges for x and y in (2), the only possible pair of numbers that sums to 7 is x = 3 and y = 4. If you choose a smaller value for x, y would have to be bigger, and (2) precludes that possibility. The same is true if you try a smaller value for y. Thus, there's only one possible pair of numbers for x and y, and the product is greater than 7. Choice (C) is correct.